Efficacy of Selective Laser Trabeculoplasty Targeting Nasal Versus Inferior 180-degree

The purpose of this study to optimize Selective Laser Trabeculoplasty (SLT) application when used in the management of open angle glaucoma (OAG)

Study Overview

• Status: Completed
• Conditions: Open Angle Glaucoma
• Intervention / Treatment: Procedure: Nasal 180° Selective Laser Trabeculoplasty (SLT); Procedure: Inferior 180° Selective Laser Trabeculoplasty (SLT)

Detailed Description

The purpose of this research is to determine the most effective method in using Selective Laser Trabeculoplasty (SLT) for lowering intraocular pressure (IOP) in patients with ocular hypertension or open-angle glaucoma. We will investigate the IOP lowering differences between nasal 180° SLT and inferior 180° SLT,. The second stage will assess the effect of repeating SLT in the opposite 180° sector after 3 months.

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, NS B3H 2Y9
      • Eye Care Centre, Victoria General Hospital
• United States
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic in Rochester

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years and older
• Ability to comprehend the study procedures and agreement to proceed with primary SLT treatment
• Diagnosis of primary or secondary open angle glaucoma or glaucoma suspects with ocular hypertension
• Bilateral disease
• Pre-SLT IOP >21 mmHg measured at least twice during patient's lifetime with or without medication
• Open angles with moderate to intense trabecular pigmentation
• Mild to moderate visual field defects (24-2 standard mean deviations better than the Swedish interactive thresholding algorithm standard of 12 dB)
• No adequate IOP control (low treatment compliance, substantial adverse effects with eyedrops, and at least 2 IOP measurements higher than the individualized target IOP)

Exclusion Criteria:

• Unwilling or unable to give consent
• Unable to attend scheduled post-operative visits
• Previous history of either laser treatment or intraocular surgery, except for non-complicated cataract surgery (performed >6 months before SLT)
• History of ocular trauma
• Narrow angles
• Retinal detachment
• Active iris neovascularization or active proliferative retinopathy
• Active uveitis
• Monocular patients
• Current use of steroids (ocular, periocular, or systemic)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Nasal 180° Selective Laser Trabeculoplasty (SLT); The Nasal 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye. After 90 days, the Inferior 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye.	Procedure: Nasal 180° Selective Laser Trabeculoplasty (SLT); The Nasal 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye. As per standard procedure, the laser will initially be set at 0.8 mJ (or 0.4 mJ for heavily pigmented TM). The energy level will then be adjusted in 0.1 mJ increments: increased until micro-bubble formation is observed or decreased if bubbles are noted. The desired endpoint is the production of a few fine 'champagne bubbles' every 2-3 laser spots. Larger gas bubbles and trabecular meshwork blanching will require the operator to titrate the power downwards in 0.1 mJ increments. Prophylactic IOP lowering and anti-inflammatory drops will be left to physician preference.; Procedure: Inferior 180° Selective Laser Trabeculoplasty (SLT); The Inferior 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye. As per standard procedure, the laser will initially be set at 0.8 mJ (or 0.4 mJ for heavily pigmented TM). The energy level will then be adjusted in 0.1 mJ increments: increased until micro-bubble formation is observed or decreased if bubbles are noted. The desired endpoint is the production of a few fine 'champagne bubbles' every 2-3 laser spots. Larger gas bubbles and trabecular meshwork blanching will require the operator to titrate the power downwards in 0.1 mJ increments. Prophylactic IOP lowering and anti-inflammatory drops will be left to physician preference.
Experimental: Inferior 180° Selective Laser Trabeculoplasty (SLT); The Inferior 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye. After 90 days, the Nasal 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye.	Procedure: Nasal 180° Selective Laser Trabeculoplasty (SLT); The Nasal 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye. As per standard procedure, the laser will initially be set at 0.8 mJ (or 0.4 mJ for heavily pigmented TM). The energy level will then be adjusted in 0.1 mJ increments: increased until micro-bubble formation is observed or decreased if bubbles are noted. The desired endpoint is the production of a few fine 'champagne bubbles' every 2-3 laser spots. Larger gas bubbles and trabecular meshwork blanching will require the operator to titrate the power downwards in 0.1 mJ increments. Prophylactic IOP lowering and anti-inflammatory drops will be left to physician preference.; Procedure: Inferior 180° Selective Laser Trabeculoplasty (SLT); The Inferior 180° Selective Laser Trabeculoplasty (SLT) will be performed on the right eye. As per standard procedure, the laser will initially be set at 0.8 mJ (or 0.4 mJ for heavily pigmented TM). The energy level will then be adjusted in 0.1 mJ increments: increased until micro-bubble formation is observed or decreased if bubbles are noted. The desired endpoint is the production of a few fine 'champagne bubbles' every 2-3 laser spots. Larger gas bubbles and trabecular meshwork blanching will require the operator to titrate the power downwards in 0.1 mJ increments. Prophylactic IOP lowering and anti-inflammatory drops will be left to physician preference.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in mean intraocular pressure (IOP)	During each visit, two consecutive IOP measurements will be obtained per eye, and the average of these values will be reported.	Baseline, 3 months, 6 months, 9 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in intraocular pressure (IOP)	Change in intraocular pressure (IOP), reported as a percentage	Baseline, 3 months, 6 months, 9 months
Intraocular pressure (IOP) lowering eye drops	Total number of patients that did not need intraocular pressure (IOP) lowering drops after the selective laser trabeculoplasty (SLT)	9 months

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Investigators: Principal Investigator: Arthur Sit, Mayo Clinic

Publications and helpful links

Helpful Links

• Mayo Clinic Clinical Trials

Study record dates

Study Major Dates

• Study Start (Actual): January 6, 2025
• Primary Completion (Actual): November 10, 2025
• Study Completion (Actual): November 10, 2025

Study Registration Dates

• First Submitted: February 24, 2025
• First Submitted That Met QC Criteria: February 24, 2025
• First Posted (Actual): February 28, 2025

Study Record Updates

• Last Update Posted (Actual): January 7, 2026
• Last Update Submitted That Met QC Criteria: January 5, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Glaucoma; Glaucoma, Open-Angle
• Other Study ID Numbers: 24-008197

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No